A model-specific approach focuses on a certain type of models, and explores complexity based on structural characteristics. For example, Bianchini et al. [1]}, [2]} and Hanin et al. [3]} study model complexity of FCNNs, Bengio and Delalleau [4]}, [5]} focus on model complexity of sum-product networks. Moreover, some studies further propose constraints on the activation functions to constrain the nonlinearity properties. For example, Liang et al. [6]} assume that activation functions \(\sigma (\cdot )\)  satisfy \(\sigma (z) = \sigma ^{\prime }(z)z\) .
